Why is the IRS asking for my 2015 return?

I filed Ch. 7 in late May. I listed the IRS as a creditor in regard to unpaid tax debts for 2011 and 2012. I have not yet filed my 2004 taxes. (I filed for an extension in April.) A few days ago, I received a letter from the IRS stating that I must file my 2015 return immediately or they may file a motion to have the bankruptcy “converted or dismissed.”

What is the IRS up to? What does my 2015 return have to do with the bankruptcy??